Evil things

[Nilpaurion Felagund]

...but [the Atani] should have a virtue to shape their life, amid the powers and chances of the world, beyond the music of the Ainur, which is fate to all things else.

(The Silmarillion 1 - emphasis mine)

Think Physics: If I apply force to a particle(Elves and Arda-bound Ainur), they move in a certain direction in accordance to Newton's laws of motions(the Music of the Ainur). A nonparticle - gas, for example(Men) do not adhere to the said law. Even though the force applied(the powers and the chances of the world) is already governed by Newton's laws, its effect on the gas is not. They could move in whatever direction, no matter how many forces you apply to force them into a direction you desire.

It's not the Music that Men change, it's how they react to what the Music has made. Case in point: Ar-Pharazôn's assault of Valinor. Sauron acts the way he is in Númenor because it was ordained by the Music. The Valar warning the Númenóreans is of the same nature. However, Ar-Pharazôn could have chosen not to attack Valinor, continue with the assault, or even conquer Middle-earth regardless of everything else that happens. That's the freedom of Men.

I'm not speaking about the nature of magic...well...except for this.

(so, Numenor is not toppled over by corporeal Eru with an enormous spade, but is swept over with a tide. And tide is natural event)

Yes, but the rift that caused the said tide was not natural - no other reports of giant rifts that swallowed islands were ever heard of in Middle-earth.